Battery adapter



FIG. 1 is a front isometric view of a battery adapter showing our design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front plan view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a rear plan view thereof;

FIG. 7 is a left side elevational view thereof; and,

FIG. 8 is a rear isometric view thereof. 

The ornamental design for a battery adapter, as shown and described. 